U.S. Pat. No. 5,055,697 discloses an infrared illuminator for use in a surveillance system where it is desired to direct a beam of infrared (IR) radiation to illuminate a desired area. The illuminator comprises a radiation filter, which is disposed in the path of the beam for selectively absorbing visible light and passing infrared radiation emitted by a light source within the illuminator.
It is known in the prior art to provide an IR light device having one or more IR light emitting diodes, which device may be mounted on a vehicle to emit IR light to illuminate a desired area. Night vision goggles may be used in conjunction with such an IR light device, wherein the night vision goggles can sense radiation invisible to a human observer.